【Abstract】 Objective] with the TUNEL labeling method and transmission electron

microscopy to observe the cartilage after impact injury in the evolution of chondrocyte apoptosis. [Method] 56 healthy adult New Zealand white rabbits were randomly divided into high and low energy groups, each of 28 randomly selected side of the hind

limbs of the experimental group, on the other side of the control group; different weights of the hammer hit the inside of the femur condylar cartilage damage caused by the different. After 4 d, 1,2,4,8,16,32 weeks to collect specimens, each time group 4

rabbits, carried out TUNEL labeling method and transmission electron microscopy to observe the apoptosis of chondrocytes. [Results] In the control group, specimens from the middle layer and calcified cartilage layer, apoptotic cells. Low-energy group, after

injury 4 d, 1,2-week specimens, cartilage intermediate layer of the transitional layer and apoptotic cells, the apoptotic rate between the control group had no statistical significance; 4 weeks after the specimen significantly reduced in apoptotic cells,

Recent studies have shown that osteoarthritis and cartilage injury in vitro model,

can be observed in chondrocyte apoptosis. With the increasing severity of osteoarthritis, cartilage cells, also increases the rate of apoptosis, mechanical damage can also induce chondrocyte apoptosis, which may be cartilage cells to mechanical damage, one of the earliest reactions [1,2] . Articular cartilage in vivo after injury by impact, cartilage cell apoptosis rate in the evolution of a lack of sufficient knowledge of the people. This experiment Newberry, Vrahas model based on the rabbit medial

femoral condylar cartilage of different models, with the TUNEL labeling method and transmission electron microscopy observation of cartilage injury in the evolution of chondrocyte apoptosis.

1 Materials and methods

1.1 Animals and Grouping

56 healthy adult rabbits, of either sex, weighing 3.0 ~ 3.5 kg, were randomly divided into light and heavy two groups of 28, randomly selected side of the hind limbs of the experimental group, on the other side of the control group. And then randomly divided

into two after 4 d, 1,2,4,8,16,32 weeks 7 hours groups, each with four animals.

and transmission electron microscopy to observe the apoptosis of chondrocytes.

1.3 Morphological observation

1.3.1 drawn, fixed

After the expiration of each group to observe, in the same location with a sharp

double-sided blade Department subchondral bone were cut 0.5 cm × 0.4 cm × 0.2 cm of cartilage, subchondral bone and did not take to avoid the damage due to the process of specimen decalcified cells, causing false positive. Specimens cut two equal parts, one

were immediately placed in 10% neutral formalin solution at room temperature for a fixed 24h, paraffin-embedded tissue blocks for serial sections, sheet thickness of 51 μm, made of pathology standby. The other one were prepared to do transmission electron

Each one TUNEL marker sectioning microscopy camera microscope (magnification 10 × 40), randomly selected four vision to capture the image into the computer, and the analysis system of doing image analysis, using target count, determination of chondrocyte apoptosis rate, obtained after the arithmetic mean apoptosis rate of each slice. Reposted elsewhere in the paper for free download http://

1.5 Statistical analysis

With the SPSS 12.0 statistical software package, according to high and low energy group and the corresponding control group were compared to 22, using t test, take 95% confidence interval were observed in all experimental groups and control group

the rate of chondrocyte apoptosis in the availability and Statistics learning differences.

2 Results

Postoperative survival of all experimental animals were drawn to the scheduled time, incision healed well and no infection in 1 case.

2.1 TUNEL labeling observed rate of chondrocyte apoptosis

Cartilage cell nucleus orange for apoptotic cells, blue for the normal cells. Specimens in the control group in the middle layer and the calcified cartilage layer, apoptoticcells.